manneddian founder kevin mandia, says more than 90% of the attacks he sees come from china and are nearly impossible to stop. >> we've gone from a "we must prevent every attack from occurring" to more the mindset are, "these attacks are inevitable but let's make sure we keep the attackers from our crown jewels." >> reporter: you're saying we shouldn't spend all that much time trying to prevent everything because it can't be done. >> right now you can't do it. >> reporter: mandia says cyber defenses can be improved if companies share more information about the weak-ins. >> everybody needs to get smarter from each breach. almost like a neighborhood watch. we'd all get smatter about that robbery. >> reporter: but companies want some legal protections before sharing information. they're worried revealing details of attacks cowl weaken them with competitors and expose them to investor lawsuits. cyber spies have already stolen hundreds of billions of dollars in corporate secrets everything from plans for military hardware to paint formulas. but mandia warns hackers could do even greater damage.